As a result of fuel shortage, inflation of gasoline prices and high labor cost, self-service gasoline stations from which gasoline is purchased at a reduced rate have become popular. However, for various reasons, ladies and business men have not utilized self-service gasoline pumps to a maximum extent.
The cap on gasoline tanks are often covered with dirt and grease which results in a strong likelihood that the consumer will soil his hands and possibly his clothes when the cap is removed and replaced.
In view of emission control standards established to protect the environment, vehicle designers have developed systems to prevent leakage of fuel and paper from the gas tank. Improper connection of a gas cap to a vehicle gas tank presents a potential fire hazard and also permits leakage of vapor from the tank of the vehicle.
In addition to numerous problems encountered by unskilled persons removing and replacing a gas cap, service station attendants occasionally forget to replace the cap or replace the cap improperly resulting in loss of the gas cap.
U.S. Pat. No. 1,810,019; U.S. Pat. No. 1,818,608; U.S. Pat. No. 2,503,031; and U.S. Pat. No. 2,765,948 disclose self-closing caps for fuel tanks, radiators and the like.
Self-closing caps heretofore devised are not suitable for replacement of conventional gas caps, radiator caps and the like on modern vehicles without substantial modification of the neck of the tank. Self-closing caps heretofore devised have not offered sealing capability required to meet existing emission control regulations and to permit use of the cap or filling the tank without removal of the cap or alternatively to permit removal of the cap if it is deemed expedient to do so without the use of tools.